Number of molecules or atoms in a given mass or number of moles
This type of question, asked 5 times: 26 Apr 2025 S2, 18 Apr 2026 S2, 20 Apr 2026 S2, 13 May 2026 S1, 13 May 2026 S2. All 5 questions below, oldest first.
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Question 1
26 Apr 2025 S2
51Calculate number of molecules present in 5.4 g of urea (Molar mass of urea =60 g mol−1 ).
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Question 2
18 Apr 2026 S2
1Find the number of molecules present in 70 g dinitrogen.
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Question 3
20 Apr 2026 S2
1What is the number of molecules in 2.125 g of ammonia?
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Question 4
13 May 2026 S1
1Calculate the number of molecules in 2 mol of MgO.
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Question 5
13 May 2026 S2
1Calculate the number of atoms in each of the following.
(a) 11.2 g nitrogen (b) 1.15 g sodium
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